When a wellbore is drilled, in-situ stress field creates a stress concentration or perturbation around the wellbore. When this stress concentration exceeds the strength of the rock, failure can occur in either compression or tension. Stress-induced wellbore failures are commonly referred to as induced tensile fractures and breakouts. Induced tensile fractures are small-scale fractures that generally occur only in the wall of the borehole and follow the stress concentration around the wellbore. Due to their small size, these fractures are sometimes only detected through detailed wellbore imaging. Because these fractures generally result from the stress concentration existing around the wellbore, their location around the wellbore (referred to in this document as induced tensile fracture orientation) and their angle with respect to the borehole axis (referred to in this document as induced tensile fracture trace angle) may be directly related to the magnitude and orientation of the stress concentration around the wellbore as well as the in-situ (far-field) stress.
Knowledge of formation parameters such as in-situ stress field can be helpful in wellbore stability design, fracture modeling, and production optimization among others. Taking into account the in-situ stress field and the resulting near-wellbore stress concentration may be particularly important in the design of a wellbore, as the amount of stress may be directly related to wellbore wall failures. As a result, accurately and efficiently estimating the in-situ stress field is an important part of increasing overall efficiency of the operation. The following disclosure addresses these and other issues.